Airco D.H.1

The Airco D.H.1 was the first production aircraft designed by Geoffrey de Havilland after his appointment as Chief Designer for the Aircraft Manufacturing Co. Ltd in June 1914. It was a pusher biplane, designated as a reconnaissance fighter. Although it was only produced in small numbers it was significant as the direct predecessor of the D.H.2 single seat fighter.

The last aircraft designed by de Havilland at the Royal Aircraft Factory had been tractor types, but in 1914 interrupter gear had not yet been developed. The War Office indicated that all future aircraft were to be pushers, in order to provide the observer/ gunner with the best possible field of fire, and de Havilland responded with the D.H.1.

This was a fairly conventional twin boom, two bay wire braced pusher biplane, of fabric covered wooden construction, and with two spar mainplanes with internal wire bracing. The two crew members sat in separate cockpits in front of the wings, with the gunner/ observer in the front cockpit. Both cockpits were equipped with flight controls. The front cockpit also contained the single .303in Lewis gun, which was mounted on a telescoping pedestal.

The prototype D.H.1 had three unusual features. It used coil spring suspension in the undercarriage, had elementary oleo legs and had air brakes, in the form of three feet long auxiliary aerofoils attached to the sides of the fuselage. These could be rotated through ninety degrees to act as brakes. Of these features only the oleo legs survived into the production aircraft.

The D.H.1 was powered by a 70hp air-cooled Renault engine. Most sources indicate that it was originally designed to use a 120hp water cooled Beardmore engine, although a 100ph Green engine is also mentioned as a possibility. The majority of the 100 production aircraft that were eventually ordered were produced as the D.H.1A, and were powered by the Beardmore engine.

The prototype D.H.1 made its maiden flight in January 1915 at Hendon, with Geoffrey de Havilland at the controls. Tests showed that the aircraft was a stable flier, but that the airbrakes were ineffective. The airbrakes were removed from the prototype, while the spring suspension was abandoned on production aircraft, most of which were built by Savages Limited of King's Lynn, previously a manufacture of fairground equipment.

The D.H.1 did not see much active service. Six aircraft joined No.15 Squadron in the Middle East during 1916, where they were used as escort fighters, remaining in use at least into 1917. Twenty four aircraft went to Home Defence squadrons, and 43 to training units. The type remained in front line use until early 1917 before being relegated to second line duties. The last aircraft were withdrawn late in 1918.

1916 six go to Middle East Brigade for use by No. 14 Squadron
Home Defence squadrons get 24, 43 go to training units
Remained operational to early 1917 when relegated to second line duties, finally withdrawn end of 1918

By the time the D.H.1 had entered full production the first single-seat D.H.2 scout had already made its maiden flight (July 1915). This was effectively a smaller version of the D.H.1, and was one of the most important British fighters in the middle years of the First World War.